The invention relates to a locking element for a plastic drawing-in rod for the profile-forming connection between upholstery covering materials, with a rope-shaped holding element on the upholstery side, for upholstered furniture and similar upholstered parts, such as seat parts and back parts.
For upholstered furniture and similar upholstered parts, such as seat parts and back parts particularly of automobile seats, drawing-in rods are used for the purpose of bringing the upholstery material, usually a foam material, the outside of which is covered by a covering material and which is mounted on a suitable backing, into a desired shape appropriate for the seat. For this, the covering material is sewn to the sewing-on flag of the drawing-in rod and the drawing-in rod, so prepared, is pulled through a material slot essentially transversely to the outer surface of the covering material lying on the upholstery material into the upholstery material and fixed, as a result of which a seam-like, so-called blind tacking with appropriate profiled curvatures is produced on either side of the blind tacking.
For fixing the drawing-in rod in the upholstery material, the use of C-shaped metal clips as locking elements is known, one end of which engages the drawing-in rod and the other the rope-shaped holding element on the upholstery side, usually a metal wire fastened in the upholstery substructure. The inner side of one of the two end legs of the C-shaped profile forms a seat for the rope-shaped holding element on the upholstery side, while the other end leg of the C-shaped profile engages a bushing opening incorporated in the drawing-in rod at the respective, required connecting site.
In practice, this known type of connection between the drawing-in rod and the holding element on the upholstery side turns out to be time consuming and work intensive to a high degree and, in addition, requires more material for the drawing-in rod. This is due to the fact that, before the drawing-in rod is inserted into the upholstery material at the connection sites, which change with different applications, bushing openings must be incorporated in the appropriately massive drawing-in rod, which is dimensioned sufficiently large to accommodate the metal clips as locking elements. Moreover, for connecting the metal clips to the drawing-in rod, heavy, usually pneumatically operated special locking pliers are required, which frequently can be handled only with difficulty under the given space conditions.